tape: update user docu

This commit is contained in:
Dietmar Maurer 2020-12-21 12:13:35 +01:00
parent 1e20f819d5
commit 54d968664a

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@ -2,15 +2,24 @@ Tape Backup
===========
Our tape backup solution provides a easy way to store datastore
contents on a tape. This increases data safety because you get:
contents to a tape. This increases data safety because you get:
- an additional copy of the data
- to a different media type (tape)
- to an additional location (you can move tape offsite)
Tape backups do not provide random access to the stored
data. Instead, you need to restore the data to disk before you can
access it again.
Statistics show that 95% of all restore jobs restores the last
backup. Restore requests further declines the older the data gets.
Considering that, tape backup may also help to reduce disk usage,
because you can safely remove data from disk once archived on tape.
This is especially true if you need to keep data for several years.
Tape backups do not provide random access to the stored data. Instead,
you need to restore the data to disk before you can access it
again. Also, if you store your tapes offsite (using some kind of tape
vaulting service), you need to bring them onsite before you can do any
restore. So please consider that restores from tapes can take much
longer than restores from disk.
Tape Technology Primer
@ -20,7 +29,16 @@ Tape Technology Primer
As of 2021, the only broadly available tape technology standard is
`Linear Tape Open`_, and different vendors offers LTO Ultrium tape
drives and autoloaders.
drives, autoloaders and LTO tape cartridges.
Of cause, there are a few vendor offering proprietary drives with
slight advantages in performance and capacity, but they have
significat disadvantages:
- proprietary (single vendor)
- a much higher purchase cost
So we currently do no test such drives.
In general, LTO tapes offer the following advantages:
@ -31,6 +49,10 @@ In general, LTO tapes offer the following advantages:
- Movable (storable inside vault)
- Multiple vendors (for both media and drives)
Please note that `Proxmox Backup Server`_ already stores compressed
data, so we do not need/use the tape compression feature. Same applies
to encryption.
Supported Hardware
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